linux/drivers/power/pcf50633-charger.c
Krzysztof Kozlowski 297d716f62 power_supply: Change ownership from driver to core
Change the ownership of power_supply structure from each driver
implementing the class to the power supply core.

The patch changes power_supply_register() function thus all drivers
implementing power supply class are adjusted.

Each driver provides the implementation of power supply. However it
should not be the owner of power supply class instance because it is
exposed by core to other subsystems with power_supply_get_by_name().
These other subsystems have no knowledge when the driver will unregister
the power supply. This leads to several issues when driver is unbound -
mostly because user of power supply accesses freed memory.

Instead let the core own the instance of struct 'power_supply'.  Other
users of this power supply will still access valid memory because it
will be freed when device reference count reaches 0. Currently this
means "it will leak" but power_supply_put() call in next patches will
solve it.

This solves invalid memory references in following race condition
scenario:

Thread 1: charger manager
Thread 2: power supply driver, used by charger manager

THREAD 1 (charger manager)         THREAD 2 (power supply driver)
==========================         ==============================
psy = power_supply_get_by_name()
                                   Driver unbind, .remove
                                     power_supply_unregister()
                                     Device fully removed
psy->get_property()

The 'get_property' call is executed in invalid context because the driver was
unbound and struct 'power_supply' memory was freed.

This could be observed easily with charger manager driver (here compiled
with max17040 fuel gauge):

$ cat /sys/devices/virtual/power_supply/cm-battery/capacity &
$ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind
[   55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   55.732584] pgd = d98d4000
[   55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000
[   55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[   55.746210] Modules linked in:
[   55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G        W       3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496
[   55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[   55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000
[   55.771647] PC is at 0x0
[   55.774182] LR is at charger_get_property+0x2f4/0x36c
[   55.779201] pc : [<00000000>]    lr : [<c034b0b4>]    psr: 60000013
[   55.779201] sp : daf55e90  ip : 00000003  fp : 00000000
[   55.790657] r10: 00000000  r9 : c06e2878  r8 : d9b26c68
[   55.795865] r7 : dad81610  r6 : daec7410  r5 : daf55ebc  r4 : 00000000
[   55.802367] r3 : 00000000  r2 : daf55ebc  r1 : 0000002a  r0 : d9b26c68
[   55.808879] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   55.815994] Control: 10c5387d  Table: 598d406a  DAC: 00000015
[   55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210)
[   55.827451] Stack: (0xdaf55e90 to 0xdaf56000)
[   55.831795] 5e80:                                     60000013 c01459c4 0000002a c06f8ef8
[   55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4
[   55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80
[   55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001
[   55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000
[   55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000
[   55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124
[   55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550
[   55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364
[   55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c
[   55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000
[   55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000
[   55.929744] [<c034b0b4>] (charger_get_property) from [<c0346864>] (power_supply_show_property+0x48/0x20c)
[   55.939286] [<c0346864>] (power_supply_show_property) from [<c027f25c>] (dev_attr_show+0x1c/0x48)
[   55.948130] [<c027f25c>] (dev_attr_show) from [<c0146218>] (sysfs_kf_seq_show+0x84/0x104)
[   55.956298] [<c0146218>] (sysfs_kf_seq_show) from [<c0144c78>] (kernfs_seq_show+0x24/0x28)
[   55.964536] [<c0144c78>] (kernfs_seq_show) from [<c0107f90>] (seq_read+0x1b0/0x484)
[   55.972172] [<c0107f90>] (seq_read) from [<c00e53dc>] (__vfs_read+0x18/0x4c)
[   55.979188] [<c00e53dc>] (__vfs_read) from [<c00e548c>] (vfs_read+0x7c/0x100)
[   55.986304] [<c00e548c>] (vfs_read) from [<c00e5550>] (SyS_read+0x40/0x8c)
[   55.993164] [<c00e5550>] (SyS_read) from [<c000f1a0>] (ret_fast_syscall+0x0/0x48)
[   56.000626] Code: bad PC value
[   56.011652] ---[ end trace 7b64343fbdae8ef1 ]---

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

[for the nvec part]
Reviewed-by: Marc Dietrich <marvin24@gmx.de>

[for compal-laptop.c]
Acked-by: Darren Hart <dvhart@linux.intel.com>

[for the mfd part]
Acked-by: Lee Jones <lee.jones@linaro.org>

[for the hid part]
Acked-by: Jiri Kosina <jkosina@suse.cz>

[for the acpi part]
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: Sebastian Reichel <sre@kernel.org>
2015-03-13 23:15:51 +01:00

489 lines
12 KiB
C

/* NXP PCF50633 Main Battery Charger Driver
*
* (C) 2006-2008 by Openmoko, Inc.
* Author: Balaji Rao <balajirrao@openmoko.org>
* All rights reserved.
*
* Broken down from monstrous PCF50633 driver mainly by
* Harald Welte, Andy Green and Werner Almesberger
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/device.h>
#include <linux/sysfs.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/mfd/pcf50633/core.h>
#include <linux/mfd/pcf50633/mbc.h>
struct pcf50633_mbc {
struct pcf50633 *pcf;
int adapter_online;
int usb_online;
struct power_supply *usb;
struct power_supply *adapter;
struct power_supply *ac;
};
int pcf50633_mbc_usb_curlim_set(struct pcf50633 *pcf, int ma)
{
struct pcf50633_mbc *mbc = platform_get_drvdata(pcf->mbc_pdev);
int ret = 0;
u8 bits;
int charging_start = 1;
u8 mbcs2, chgmod;
unsigned int mbcc5;
if (ma >= 1000) {
bits = PCF50633_MBCC7_USB_1000mA;
ma = 1000;
} else if (ma >= 500) {
bits = PCF50633_MBCC7_USB_500mA;
ma = 500;
} else if (ma >= 100) {
bits = PCF50633_MBCC7_USB_100mA;
ma = 100;
} else {
bits = PCF50633_MBCC7_USB_SUSPEND;
charging_start = 0;
ma = 0;
}
ret = pcf50633_reg_set_bit_mask(pcf, PCF50633_REG_MBCC7,
PCF50633_MBCC7_USB_MASK, bits);
if (ret)
dev_err(pcf->dev, "error setting usb curlim to %d mA\n", ma);
else
dev_info(pcf->dev, "usb curlim to %d mA\n", ma);
/*
* We limit the charging current to be the USB current limit.
* The reason is that on pcf50633, when it enters PMU Standby mode,
* which it does when the device goes "off", the USB current limit
* reverts to the variant default. In at least one common case, that
* default is 500mA. By setting the charging current to be the same
* as the USB limit we set here before PMU standby, we enforce it only
* using the correct amount of current even when the USB current limit
* gets reset to the wrong thing
*/
if (mbc->pcf->pdata->charger_reference_current_ma) {
mbcc5 = (ma << 8) / mbc->pcf->pdata->charger_reference_current_ma;
if (mbcc5 > 255)
mbcc5 = 255;
pcf50633_reg_write(mbc->pcf, PCF50633_REG_MBCC5, mbcc5);
}
mbcs2 = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCS2);
chgmod = (mbcs2 & PCF50633_MBCS2_MBC_MASK);
/* If chgmod == BATFULL, setting chgena has no effect.
* Datasheet says we need to set resume instead but when autoresume is
* used resume doesn't work. Clear and set chgena instead.
*/
if (chgmod != PCF50633_MBCS2_MBC_BAT_FULL)
pcf50633_reg_set_bit_mask(pcf, PCF50633_REG_MBCC1,
PCF50633_MBCC1_CHGENA, PCF50633_MBCC1_CHGENA);
else {
pcf50633_reg_clear_bits(pcf, PCF50633_REG_MBCC1,
PCF50633_MBCC1_CHGENA);
pcf50633_reg_set_bit_mask(pcf, PCF50633_REG_MBCC1,
PCF50633_MBCC1_CHGENA, PCF50633_MBCC1_CHGENA);
}
power_supply_changed(mbc->usb);
return ret;
}
EXPORT_SYMBOL_GPL(pcf50633_mbc_usb_curlim_set);
int pcf50633_mbc_get_status(struct pcf50633 *pcf)
{
struct pcf50633_mbc *mbc = platform_get_drvdata(pcf->mbc_pdev);
int status = 0;
u8 chgmod;
if (!mbc)
return 0;
chgmod = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCS2)
& PCF50633_MBCS2_MBC_MASK;
if (mbc->usb_online)
status |= PCF50633_MBC_USB_ONLINE;
if (chgmod == PCF50633_MBCS2_MBC_USB_PRE ||
chgmod == PCF50633_MBCS2_MBC_USB_PRE_WAIT ||
chgmod == PCF50633_MBCS2_MBC_USB_FAST ||
chgmod == PCF50633_MBCS2_MBC_USB_FAST_WAIT)
status |= PCF50633_MBC_USB_ACTIVE;
if (mbc->adapter_online)
status |= PCF50633_MBC_ADAPTER_ONLINE;
if (chgmod == PCF50633_MBCS2_MBC_ADP_PRE ||
chgmod == PCF50633_MBCS2_MBC_ADP_PRE_WAIT ||
chgmod == PCF50633_MBCS2_MBC_ADP_FAST ||
chgmod == PCF50633_MBCS2_MBC_ADP_FAST_WAIT)
status |= PCF50633_MBC_ADAPTER_ACTIVE;
return status;
}
EXPORT_SYMBOL_GPL(pcf50633_mbc_get_status);
int pcf50633_mbc_get_usb_online_status(struct pcf50633 *pcf)
{
struct pcf50633_mbc *mbc = platform_get_drvdata(pcf->mbc_pdev);
if (!mbc)
return 0;
return mbc->usb_online;
}
EXPORT_SYMBOL_GPL(pcf50633_mbc_get_usb_online_status);
static ssize_t
show_chgmode(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pcf50633_mbc *mbc = dev_get_drvdata(dev);
u8 mbcs2 = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCS2);
u8 chgmod = (mbcs2 & PCF50633_MBCS2_MBC_MASK);
return sprintf(buf, "%d\n", chgmod);
}
static DEVICE_ATTR(chgmode, S_IRUGO, show_chgmode, NULL);
static ssize_t
show_usblim(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pcf50633_mbc *mbc = dev_get_drvdata(dev);
u8 usblim = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCC7) &
PCF50633_MBCC7_USB_MASK;
unsigned int ma;
if (usblim == PCF50633_MBCC7_USB_1000mA)
ma = 1000;
else if (usblim == PCF50633_MBCC7_USB_500mA)
ma = 500;
else if (usblim == PCF50633_MBCC7_USB_100mA)
ma = 100;
else
ma = 0;
return sprintf(buf, "%u\n", ma);
}
static ssize_t set_usblim(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct pcf50633_mbc *mbc = dev_get_drvdata(dev);
unsigned long ma;
int ret;
ret = kstrtoul(buf, 10, &ma);
if (ret)
return ret;
pcf50633_mbc_usb_curlim_set(mbc->pcf, ma);
return count;
}
static DEVICE_ATTR(usb_curlim, S_IRUGO | S_IWUSR, show_usblim, set_usblim);
static ssize_t
show_chglim(struct device *dev, struct device_attribute *attr, char *buf)
{
struct pcf50633_mbc *mbc = dev_get_drvdata(dev);
u8 mbcc5 = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCC5);
unsigned int ma;
if (!mbc->pcf->pdata->charger_reference_current_ma)
return -ENODEV;
ma = (mbc->pcf->pdata->charger_reference_current_ma * mbcc5) >> 8;
return sprintf(buf, "%u\n", ma);
}
static ssize_t set_chglim(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct pcf50633_mbc *mbc = dev_get_drvdata(dev);
unsigned long ma;
unsigned int mbcc5;
int ret;
if (!mbc->pcf->pdata->charger_reference_current_ma)
return -ENODEV;
ret = kstrtoul(buf, 10, &ma);
if (ret)
return ret;
mbcc5 = (ma << 8) / mbc->pcf->pdata->charger_reference_current_ma;
if (mbcc5 > 255)
mbcc5 = 255;
pcf50633_reg_write(mbc->pcf, PCF50633_REG_MBCC5, mbcc5);
return count;
}
/*
* This attribute allows to change MBC charging limit on the fly
* independently of usb current limit. It also gets set automatically every
* time usb current limit is changed.
*/
static DEVICE_ATTR(chg_curlim, S_IRUGO | S_IWUSR, show_chglim, set_chglim);
static struct attribute *pcf50633_mbc_sysfs_entries[] = {
&dev_attr_chgmode.attr,
&dev_attr_usb_curlim.attr,
&dev_attr_chg_curlim.attr,
NULL,
};
static struct attribute_group mbc_attr_group = {
.name = NULL, /* put in device directory */
.attrs = pcf50633_mbc_sysfs_entries,
};
static void
pcf50633_mbc_irq_handler(int irq, void *data)
{
struct pcf50633_mbc *mbc = data;
/* USB */
if (irq == PCF50633_IRQ_USBINS) {
mbc->usb_online = 1;
} else if (irq == PCF50633_IRQ_USBREM) {
mbc->usb_online = 0;
pcf50633_mbc_usb_curlim_set(mbc->pcf, 0);
}
/* Adapter */
if (irq == PCF50633_IRQ_ADPINS)
mbc->adapter_online = 1;
else if (irq == PCF50633_IRQ_ADPREM)
mbc->adapter_online = 0;
power_supply_changed(mbc->ac);
power_supply_changed(mbc->usb);
power_supply_changed(mbc->adapter);
if (mbc->pcf->pdata->mbc_event_callback)
mbc->pcf->pdata->mbc_event_callback(mbc->pcf, irq);
}
static int adapter_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct pcf50633_mbc *mbc = power_supply_get_drvdata(psy);
int ret = 0;
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = mbc->adapter_online;
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static int usb_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct pcf50633_mbc *mbc = power_supply_get_drvdata(psy);
int ret = 0;
u8 usblim = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCC7) &
PCF50633_MBCC7_USB_MASK;
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = mbc->usb_online &&
(usblim <= PCF50633_MBCC7_USB_500mA);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static int ac_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct pcf50633_mbc *mbc = power_supply_get_drvdata(psy);
int ret = 0;
u8 usblim = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCC7) &
PCF50633_MBCC7_USB_MASK;
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = mbc->usb_online &&
(usblim == PCF50633_MBCC7_USB_1000mA);
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static enum power_supply_property power_props[] = {
POWER_SUPPLY_PROP_ONLINE,
};
static const u8 mbc_irq_handlers[] = {
PCF50633_IRQ_ADPINS,
PCF50633_IRQ_ADPREM,
PCF50633_IRQ_USBINS,
PCF50633_IRQ_USBREM,
PCF50633_IRQ_BATFULL,
PCF50633_IRQ_CHGHALT,
PCF50633_IRQ_THLIMON,
PCF50633_IRQ_THLIMOFF,
PCF50633_IRQ_USBLIMON,
PCF50633_IRQ_USBLIMOFF,
PCF50633_IRQ_LOWSYS,
PCF50633_IRQ_LOWBAT,
};
static const struct power_supply_desc pcf50633_mbc_adapter_desc = {
.name = "adapter",
.type = POWER_SUPPLY_TYPE_MAINS,
.properties = power_props,
.num_properties = ARRAY_SIZE(power_props),
.get_property = &adapter_get_property,
};
static const struct power_supply_desc pcf50633_mbc_usb_desc = {
.name = "usb",
.type = POWER_SUPPLY_TYPE_USB,
.properties = power_props,
.num_properties = ARRAY_SIZE(power_props),
.get_property = usb_get_property,
};
static const struct power_supply_desc pcf50633_mbc_ac_desc = {
.name = "ac",
.type = POWER_SUPPLY_TYPE_MAINS,
.properties = power_props,
.num_properties = ARRAY_SIZE(power_props),
.get_property = ac_get_property,
};
static int pcf50633_mbc_probe(struct platform_device *pdev)
{
struct power_supply_config psy_cfg = {};
struct pcf50633_mbc *mbc;
int ret;
int i;
u8 mbcs1;
mbc = devm_kzalloc(&pdev->dev, sizeof(*mbc), GFP_KERNEL);
if (!mbc)
return -ENOMEM;
platform_set_drvdata(pdev, mbc);
mbc->pcf = dev_to_pcf50633(pdev->dev.parent);
/* Set up IRQ handlers */
for (i = 0; i < ARRAY_SIZE(mbc_irq_handlers); i++)
pcf50633_register_irq(mbc->pcf, mbc_irq_handlers[i],
pcf50633_mbc_irq_handler, mbc);
psy_cfg.supplied_to = mbc->pcf->pdata->batteries;
psy_cfg.num_supplicants = mbc->pcf->pdata->num_batteries;
psy_cfg.drv_data = mbc;
/* Create power supplies */
mbc->adapter = power_supply_register(&pdev->dev,
&pcf50633_mbc_adapter_desc,
&psy_cfg);
if (IS_ERR(mbc->adapter)) {
dev_err(mbc->pcf->dev, "failed to register adapter\n");
ret = PTR_ERR(mbc->adapter);
return ret;
}
mbc->usb = power_supply_register(&pdev->dev, &pcf50633_mbc_usb_desc,
&psy_cfg);
if (IS_ERR(mbc->usb)) {
dev_err(mbc->pcf->dev, "failed to register usb\n");
power_supply_unregister(mbc->adapter);
ret = PTR_ERR(mbc->usb);
return ret;
}
mbc->ac = power_supply_register(&pdev->dev, &pcf50633_mbc_ac_desc,
&psy_cfg);
if (IS_ERR(mbc->ac)) {
dev_err(mbc->pcf->dev, "failed to register ac\n");
power_supply_unregister(mbc->adapter);
power_supply_unregister(mbc->usb);
ret = PTR_ERR(mbc->ac);
return ret;
}
ret = sysfs_create_group(&pdev->dev.kobj, &mbc_attr_group);
if (ret)
dev_err(mbc->pcf->dev, "failed to create sysfs entries\n");
mbcs1 = pcf50633_reg_read(mbc->pcf, PCF50633_REG_MBCS1);
if (mbcs1 & PCF50633_MBCS1_USBPRES)
pcf50633_mbc_irq_handler(PCF50633_IRQ_USBINS, mbc);
if (mbcs1 & PCF50633_MBCS1_ADAPTPRES)
pcf50633_mbc_irq_handler(PCF50633_IRQ_ADPINS, mbc);
return 0;
}
static int pcf50633_mbc_remove(struct platform_device *pdev)
{
struct pcf50633_mbc *mbc = platform_get_drvdata(pdev);
int i;
/* Remove IRQ handlers */
for (i = 0; i < ARRAY_SIZE(mbc_irq_handlers); i++)
pcf50633_free_irq(mbc->pcf, mbc_irq_handlers[i]);
sysfs_remove_group(&pdev->dev.kobj, &mbc_attr_group);
power_supply_unregister(mbc->usb);
power_supply_unregister(mbc->adapter);
power_supply_unregister(mbc->ac);
return 0;
}
static struct platform_driver pcf50633_mbc_driver = {
.driver = {
.name = "pcf50633-mbc",
},
.probe = pcf50633_mbc_probe,
.remove = pcf50633_mbc_remove,
};
module_platform_driver(pcf50633_mbc_driver);
MODULE_AUTHOR("Balaji Rao <balajirrao@openmoko.org>");
MODULE_DESCRIPTION("PCF50633 mbc driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:pcf50633-mbc");